The present invention relates to a roller bearing device, for example, used for a main shaft of a machine tool. The present invention also relates to a method of lubricating the roller bearing.
A tapered roller bearing device is known in which the generation of heat, which is made in the bearing when the bearing is rotated at high speed, is reduced. The tapered roller bearing device is disclosed in Patent Document 1 for example.
This tapered roller bearing device includes a hole penetrating the inner ring member in the axial direction and a hole penetrating the inner ring member from the hole in the radial direction. This hole is used as an oil supplying hole. A first nozzle from which pressured oil is injected is provided in the outer ring spacer while the first nozzle is opposed to an opening of the oil supplying hole. A through-hole penetrating the inner ring spacer in the axial direction is arranged in the circumferential direction alternately with the hole in the axial direction, and a second nozzle, which is open being opposed in the bearing, is provided in the outer ring spacer.
Oil injected from the first nozzle is supplied into the hole of the inner ring member formed in the axial direction. This oil flows outward by a centrifugal force generated by the rotation of the inner ring member and is supplied to a sliding contact portion between the large end face and the inner ring flange face which is a portion from which heat is generated at the maximum. Therefore, this oil deprives the sliding contact portion of generated heat. A portion of the oil injected from the first nozzle deprives the inner ring member of generated heat when the oil flows in the penetrating hole of the inner ring member. The oil injected from the second nozzle enters the inside of the bearing and lubricates a rolling contact face inside the bearing.
Patent Document 1
JP-A-8-270660
According to the tapered roller bearing device, heat generated when the tapered rollers are rolling can be removed, and the rolling contact face can be lubricated. However, according to the technique of the tapered roller bearing device, it is impossible to lubricate the inside of the bearing according to the rotating speed of the inner ring member. Therefore, under certain circumstances, an unnecessarily large quantity of lubricating oil is supplied to the bearing, and the stirring resistance of the rollers is increased.